Effect of poor oral hygiene and periodontal pathogens on the risk of oral carcinogenesis

Background: One of the leading causes of cancer deaths worldwide, particularly in underdeveloped countries, is oral squamous cell carcinoma (OSCC). Tobacco, alcohol, and areca nuts are known risk factors, but new research suggests that chronic inflammation, microbial dysbiosis, and inadequate dental hygiene might also play a role in the development of oral cancer. Aim: There are limited data on the existence of a relationship between poor oral hygiene, periodontal pathogens, and early oral cytological indicators of oral carcinogenesis in clinically normal oral mucosa. Materials and Methods: A cross-sectional comparative study was done involving 150 individuals ( n = 50 in each group), namely: People in Group A with chronic periodontitis and inadequate dental hygiene practices; People in Group B have moderate gum disease and poor oral hygiene, whereas those in Group C have excellent gum disease and periodontal health. The degree of dental care was assessed using periodontal factors and the Oral Hygiene Index-Simplified. Micronucleus (MN) and nuclear abnormality frequency measurements were derived from exfoliative cytology of buccal mucosa. Using the polymerase chain reaction, samples of subgingival plaque were tested for Porphyromonas gingivalis , Tannerella forsythia , and Fusobacterium nucleatum . Results: Group A exhibited much more MN frequency (17.6 ± 5.7 per 1000 cells) than Group B (10.2 ± 3.9) and Group C (3.8 ± 1.7) ( P < 0.001). The nuclear abnormalities were common in Group A (70.0) compared to Group B (46.0) and Group C (12.0). In Group A, P. gingivalis and F. nucleatum were the most common (60.0 and 66.0, respectively). The positive correlation was found between MN frequency and probing pocket depth; between MN frequency and F. nucleatum . Conclusion: The relationship between oral hygiene and periodontal pathogens with cytological indicators of genomic instability in healthy oral mucosa is strongly related, implying a contributory role in oral carcinogenesis. Oral health and periodontal health should be maintained optimally to potentially have a significant preventive value in decreasing the risk of oral cancer.